


Mutually Perturbing Attractions

by radialarch



Category: Captain America (Movies)
Genre: F/M, M/M, Pining, Threesome - F/M/M
Language: English
Status: Completed
Published: 2014-10-13
Updated: 2014-10-13
Packaged: 2018-02-21 01:42:00
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,769
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2449928
Author URL: https://archiveofourown.org/users/radialarch/pseuds/radialarch
Summary: <blockquote class="userstuff">
              <p>He has to give Steve up. He has to let him go for good, because he’ll always need Steve to love him. And it’s all right to ruin himself, but he can’t ruin what Steve and Agent Carter’s got between them -- it wouldn’t be right.</p>
            </blockquote>





	Mutually Perturbing Attractions

**Author's Note:**

> This is for [Sara](/users/fallingvoices), who persuaded me to write a much happier fic than originally planned <3
> 
> Title is a reference to the excellently named [three-body problem](http://en.wikipedia.org/wiki/Three-body_problem).

Bucky remembers only fragments of the march from Azzano to base. He tried his hardest to stay upright and keep his rifle up, and he thinks he mostly succeeded. He must have slept, but what he remembers more is the terror of half-waking, convinced that he was back on that bench.

He remembers Steve, though — yeah, Steve in a new body, hair burnished like gold, and the way he snapped out orders like he’d been born for it. For three days Bucky had had Steve, had kept his six and drowned in his voice, just like old times.

He hadn’t known about Agent Carter then.

 

* * *

 

Bucky doesn’t understand, at first. Agent Carter tells Steve, “you’re late,” with her mouth very steady, and Steve grins at her for a beat too long; but then the cheers roll over them all and it shouldn’t matter, this one moment in a trampled field.

After all, Bucky’s been with Steve for a lifetime.

 

* * *

 

Steve finds Bucky trying his hardest to get drunk. Steve finds Bucky, which is familiar; Bucky swallows his drink and grins at Steve about his uniform, an easy exchange where they both know the steps.

But it’s Agent Carter in a red red dress who asks Steve to dance. She doesn’t glance at Bucky, her eyes all for Steve, and Steve looks back at her like—

— like he could spend the rest of his life with her, and Bucky feels something lurch in his chest.

 

* * *

 

All the double dates that Bucky's set them on, and he still hadn't even known to be worried.

The worst thing is this: he'd taken Steve for granted, just like everyone else.

 

* * *

 

"Have you asked her," Bucky says over drinks. "To marry you."

Steve startles. "I haven't — no," he says. "Doesn't seem fair when there's a war on."

"You'll make it," Bucky says, with a bone-deep conviction. There can be no other end to the war than this. "And she'll say yes, and you'll have a grand house somewhere with lots of kids—"

"Sounds like you've got it all planned out," Steve says, amused. "What about you, then?"

Bucky keeps his voice bright and doesn't look at Steve. "Maybe I'll go traveling. Drop by every year and spoil your kids rotten."

"Oh," Steve says. "You won't—"

Bucky doesn't wait for Steve to finish. "But what are you doing talking about this with me," he says. He thinks about giving Steve a shove but the thought of touching him sets something sharp loose in his chest. "Go talk to your girl, Rogers. She's probably waiting for you."

He turns away from Steve, takes another swallow of his drink. He can feel Steve staring at his shoulder but he leaves, after a while.

 

* * *

 

He has to give Steve up. He has to let him go for good, because he’ll always need Steve to love him. And it’s all right to ruin himself, but he can’t ruin what Steve and Agent Carter’s got between them — it wouldn’t be right.

Between the two of them, Steve is the one who deserves happiness, and the least Bucky can do is give it to him.

 

* * *

 

“Sergeant Barnes.”

Bucky doesn’t have to look up to recognize Agent Carter’s voice. He stands up automatically, some semblance of manners coming back to him; because, no matter that Agent Carter wears trousers just as often as skirts and can handle a gun better than most men, she is, unquestionably, a lady.

“Ma’am.”

Agent Carter actually smiles, a break in her habitual cool politeness. “Carter will do,” she tells him, sliding into the chair across. “We’ve not talked much, have we?”

Bucky retakes his seat. “No,” he agrees, “but you’ve got a war on and you—” _have Steve_ , he nearly says, but if he says it out loud it’s bound to come out tinged in bitter jealousy — “don’t have much time,” he finishes lamely. “I’d think you’d want to spend it with someone better than me.”

“Is that true for Steve as well?” She doesn’t waste a moment, Agent Carter — Bucky never should’ve expected any different from Steve’s gal. “Is that why you’ve been avoiding him?”

Something in Bucky’s chest goes hot and white — he’s been trying to be _good_ , trying to let Steve go, and it’s unfathomably cruel for Agent Carter to demand he spell it out.

He lets out a breath through his nose. “Told him he should spend his time with his girl," he says, as blandly as possible. “Just common sense, but Steve hasn’t got an ounce of that.”

“Oh, Barnes,” and there’s something like tenderness in Carter’s voice that makes Bucky feel like he’s going to shatter. “I am very fond of Steve, but don’t you know he’d never let you go?”

“Pardon?”

Agent Carter leans forward, reaches for the last of Bucky’s drink and downs it. Bucky watches the movement of her throat, blinks a little at the glisten of her lips.

“Do you really believe that Steve’s heart’s only big enough to love one person? _Steve_?”

A laugh tears itself out of Bucky’s throat. “He’d love the whole world, if he could,” he admits.

“Or at least two,” Agent Carter says tartly.

Bucky feels like a drowning man on the edge of shore. “So what are you saying?” he asks. “That — that we share Steve?”

He means it to sound ridiculous; he doesn’t mean for Agent Carter to smile.

“Well,” she says. “Do you think he’d mind?”

 

* * *

 

Bucky paces in front of Steve's quarters for a long time, and then walks in, quickly, before he can change his mind.

"Bucky," Steve says, surprised. And then, looking at his face, "You've talked to Peggy."

"Yeah," Bucky says, raspy. "That I did."

Steve doesn't say anything more, just looks at him with his mouth parted slightly. There's nothing self-conscious about him, just a faint pleading on his face, like he needs Bucky to understand — and Bucky steps forward, to touch Steve's jaw.

"Tell me you want this," he says, his voice trembling. "Tell me it's okay."

"Yeah, Buck," Steve says, his arms coming up to wrap around Bucky's body. "I want — yeah."

"I'm not going to be—" Bucky starts, "if you love Carter more, you should just—"

"I'd never — no, Buck," Steve says, and then he's kissing Bucky: his mouth on Bucky's mouth, stealing the rest of his words. "I ain't asking out of — it's selfish, is what it is."

"Shut up, Rogers," Bucky tells him, gripping his arms and kissing him harder. "If you had a hundred other girls, I'd still say yes, every time."

"Is it wrong, that we're like this?" Steve asks, touching his forehead to Bucky's.

“I don’t care,” Bucky says fiercely. “If you’ll have me, I don’t care.”

 

* * *

 

And things should be all right — things should be brilliant. They kiss lazily in the evenings with Steve’s hands stroking Bucky’s sides; and Bucky doesn’t care, if Steve kisses Agent Carter in the same way, or a different way altogether, as long as Steve carves out room in his world to kiss Bucky, too.

But one day Steve comes to find Bucky and tells him to come up to his quarters with an unhappy little frown, and Bucky’s left wondering what he’s missed.

 

* * *

 

When Bucky gets to Steve’s room, Agent Carter is already there, perched in the only chair in the room. Steve’s sitting on the edge of his bed, spine very straight.

“What’s going on?” Bucky asks, closing the door and leaning on it. He tries to swallow away the nervousness in his throat but it won’t go.

“Hey, Buck.” Steve greets him with a smile, and surely that’s a good thing, surely Steve’s not—

“Now look,” Steve says. “Peggy, Bucky, you know I lo—you know I love you both,” he says, taking a breath. Bucky can’t quite figure out what Agent Carter’s expression means, but he thinks she looks a bit startled.

So’s Bucky, when it comes to that. Steve’s never said — well, Bucky’s _known_ , or thought he’d known, but hearing it in Steve’s voice is different.

“And I just — you two,” Steve says, gesturing to them. “I just think, sometimes, that it’d be better if you two — because you’ve given me so much, and I want—”

“Spit it out,” Bucky says. He’s not sure where this is going but he’s curious now, and the unease that had been prickling at the back of his neck is gone.

Steve is pink across his nose, but he nods at Peggy and says, quite steadily, “Why don’t you kiss her, Buck.”

Carter turns to Steve wordlessly, but Steve holds her gaze and something in her softens; she uncrosses her legs and looks to Bucky, her entire body a challenge.

Bucky realizes he’s moving. He lurches forward, suddenly clumsy all over, and leans down to press his mouth to hers.

It’s a chaste one, the kiss — they’ve both got their mouths closed, so it’s only a dry brush of lips. Bucky draws back quickly and resists the urge to lick his lips. There’s a blush high up on Agent Carter’s face, but she’s not looking away.

“Oh, come on, Buck,” Steve says, in that slow way that means he’s got a lazy smile across his mouth. “You can do better than that. I’ve seen you do it.”

 _You’ve done it to me_ , Steve doesn’t say, but Bucky hears it all the same. “All right,” he says, drawing himself up. “Properly, then.”

He puts his hands around Agent Carter’s waist, and kisses her hard — her head falls back, and when Bucky slides his tongue across the seam of her mouth it opens at once. She bites at his lower lip: not cruel, but hard enough to leave a mark.

They’re both waiting for something, Bucky finds. Their bodies are taut against each other, but Bucky’s hands stay where they are and Carter makes no move, either.

It’s Steve who breaks the silence. “Peggy,” he says with a hint of a rasp. “Touch him.”

Steve, their Steve — their one shared point of contact. Without him they’d have nothing in common.

But Steve’s presence is so expansive, so intoxicating, that it is enough; and Carter lifts up a hand to rest it on Bucky’s chest, slides it downward.

“Nothing compared to Captain America,” she says archly. “But you’ll do.”

Bucky grins against her mouth. “You haven’t seen anything yet.”

Carter brushes a thumb across his collarbone. “No,” she says. “Shall we change that?”

“Take off his shirt,” Steve agrees. Then he clarifies: “Slowly. Make him work for it it.”

Bucky’s not looking at Agent Carter as she undoes the buttons of his shirt one by one; he’s looking at Steve, the way his face is flushed and his mouth is bitten red. Steve’s eyes are dark and Bucky feels exposed all over that’s got nothing to do with how Carter’s pushing his shirt off his shoulders.

“Bucky,” Steve says, gently chiding. “Don’t let Peggy do all the work.”

“Yessir,” Bucky says immediately. “I mean. No.”

Carter is wearing a white shirt that strains faintly over her breasts. Bucky flicks the first button open, watches the fabric part to reveal the pale, pale skin of her chest. His hands get clumsier as he goes down, and by the time her shirt’s fully open he’s trembling, just a little.

This is Steve’s girl, and Bucky is unhooking her brassiere. Underneath, her breasts are full and round. Bucky brings a hand up to cup one in his hand, gently.

“I’m not made of glass, sergeant,” Carter says, laughter in her voice. “You can touch.”

“Use your mouth,” Steve says. Bucky nearly chokes, to hear those words in Steve’s voice, but obediently bends down to take one of Carter’s nipples, carefully, between his teeth. When he runs his tongue over it, Carter makes a throaty sound, nearly a moan.

Carter’s hands are firm on him now, as Bucky mouths at her breasts — she runs her fingers across the short hair on his chest, thumbing at his nipples.

Bucky lifts her up, slides into her seat, and sets her back down on his lap. When she uncurls her legs her knee is nudging against his cock, light but with the promise of firmness to it.

“Is he hard?” Steve asks. “Do you think he’s appreciating this?”

Carter’s hand comes down onto his crotch, stroking him through the fabric. Bucky barely resists the urge to thrust up into her touch. “I rather think he is.”

“Oh, come on, Carter.” And Bucky brushes his hand up Carter’s stockinged legs, to slip a hand under her skirt into her damp panties. “Don’t pretend you’re not enjoying this, either.”

“I never said—” she starts primly, before breaking off into a sigh. “Dear god.”

“Just Barnes,” Bucky says, and slips the panties from her hips, down to her knees. “How should I do this?”

“Just one finger,” Steve tells him. “Make sure she’s ready for it.”

Carter is slick when he parts her folds; his finger slides into her easily, and she makes a muffled noise against his shoulder. “Oh, I think she’s ready, pal.”

“Two, then,” Steve concedes. “Go on.”

So Bucky presses another finger into her. Carter’s hands tighten around his shoulder.

Steve won’t stop talking. “Yeah, Buck,” he says, with breaths coming short. “Just like that. Spread your fingers a little.”

Bucky’s so hard he can barely see straight, but he sucks on a spot on Carter’s shoulder and crooks his fingers, just like Steve tells him, and when Steve tells him breathlessly to nudge her clit with his thumb, that’s it, Carter’s coming, silently and with her head tossed back.

She’s flushed and smiling in a very satisfied way when she kicks off her panties completely and turns to Bucky. “Well. I suppose I ought to return the favour.”

“Might be nice,” Bucky agrees.

“Take off your pants,” Steve tells him, and Bucky’s hands are at his belt before Steve’s even finished speaking. When he slides out of his boxers his cock springs up, flushed and red.

She doesn’t lay a hand on his cock until Steve tells her how to do it, then she follows his muttered instructions beautifully: her thumb rubbing circles around the head of his cock, and then her slim fingers wrapping around him. Bucky clenches his teeth to keep embarrassing noises from slipping out but then one of her hands slip down to tug at his balls and he chokes, his eyes rolling back as he comes.

When Bucky’s recovered he finds he can’t bear to look at Steve; Agent Carter has no such compunction, nodding her head with her eyebrows arched. “Poor thing,” she whispers into his ear. “Shall we take care of that for him?”

So Bucky forces himself to look: and oh, it’s beautiful, Steve with his face flushed all the way to his ears, his hands clenched at his sides and his cock straining against the fabric of his uniform.

“Seems only fair,” Bucky nods. He slides down from his chair to crawl across the floor until he’s kneeling by the bed, at Steve’s feet.

“Buck?” Steve sounds startled, and a little uncertain for the first time since they’ve started; and Bucky might be the one without any clothes on, but looking at Steve it’s almost as if Steve’s the one naked, self-conscious under Bucky’s gaze.

“What is it?” Bucky asks as he starts unbuckling Steve’s belt. “Lie back—”

“—and think of England,” Carter supplies, straddling one of Steve’s knees to kiss him. “Excellent advice.”

And then Bucky’s got his mouth on Steve’s cock, and Steve makes a needy noise; and it’s just Steve on his tongue, Steve bucking into his mouth —

— no, Carter’s hand on his head, subtly directing him, and Bucky hadn’t thought he could get hard again so soon but his cock makes a valiant attempt anyway.

Bucky closes his eyes and lets himself drown in the sensations: Steve heavy in his mouth, Carter’s nails lightly scratching across his scalp. Steve’s knee is bumping against his shoulder and Carter sits down on the bed, bringing up one of her stockinged feet to rest on Bucky’s thigh; and when Steve comes into his mouth it’s not even a surprise, really, just something that was always going to happen, and it’s right, it’s okay.

Bucky climbs onto the bed, limbs heavy with sleep, and curls into Steve’s chest; Peggy is right on the other side, her arm draped over their shoulders, and Steve is warm and steady under the weight of them both.

Bucky closes his eyes, and thinks, _that Agent Carter ain’t so bad, after all_.


End file.
